Presentation given by Kenneth Field at International Cartographic Conference, Dresden 2013 When one thinks of a map depicting London, generally the image that appears is of that of the map designed by Henry (Harry) Beck. It has become a design icon despite the fact that it eschews topography (other than the River Thames) and focuses on the simplified depiction of the topology of the Underground rail network. Beck’s map, designed in 1931, and first made available to London commuters in 1933, has become the image of the geography of London and, generally, the mental map that defines how London ‘works’. Station names have become synonymous with the above-ground landscape and the network is such that most of London’s landmarks can be readily located through the map. Navigating between them is a simple process and while the city above is a socio-economic and cultural soup, the simplicity of the map brings a sense of order, structure and sensibility. It is a perfect counterpoint to the chaos at street level. This paper asserts that Beck’s map is over-used in myriad ways beyond the reason for its invention. The effect of such abuse has been to dilute its own place in cartographic history. There have been many official iterations that have not always successfully married Beck’s design ideas with network changes; other metro maps have often tried to imitate but with mediocre success; and the map is perpetually used as a template for mimics and alternatives. The map has become a model for parody.